Cisco Cisco WebEx Support Center WBS29.13 Release Notes
Integrated VoIP Audio FAQs
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WebEx Support Center Release Notes and FAQs
VoIP solution will have delay of about 0.25 - 0.5 seconds, depending on a couple of factors:
1. Network congestion: VoIP solutions send the voice information over an IP network (such as the
Internet), which is a shared medium on which the packets are routed on a first-in/first-out basis.
Congestion on any of the routers between the meeting participants will delay and/or degrade the
audio.
2. Encoding process: When you speak into the microphone, the sound card in your PC captures and
digitizes the sound. This information is then broken up into data packets that are sent over the
network to the conference server(s). The conference server(s) sends these packets to the other
attendees’ PCs, where the encoding process is reversed. The encoding process for integrated VoIP
relies on audio components (microphone, speakers, and sound card), and these can vary greatly
from PC to PC. Lower quality components will produce lower quality audio.
Such delay and audio quality issues are common to the VoIP solutions offered by all the vendors—not just
WebEx. VoIP solutions offered by vendors such as Centra, et al., suffer from the same shortcomings when
compared to PSTN. Based on our testing, the delay and audio quality of WebEx VoIP is at least on par with
that of Centra's.
Q. Why do I get good quality on some VoIP calls, but not on others?
Q. Why do I get good quality on some VoIP calls, but not on others?
A. It is hard to have a straight answer to this question due to the number of possibilities. You can have a
perfect VoIP conference with a 28-Kbps connection to a country halfway around the world, followed by a
scratchy mess for a call to the next state with a 56-Kbps or a 300+-Kbps connection. The quality is almost
entirely determined by the sample rate (number of "slices" per second it uses to reproduce your voice) of
the VoIP software, plus the throughput of your internet connection. A 56-Kbps (or a 300+-Kbps LAN, for
that matter) connection does not ensure that you can move data across the Internet at that speed; the
actual speed is determined by traffic levels on all networks between the source and end point, and the
equipment capabilities at the source and end point. In general, poor-quality transmissions are a result of
traffic and cannot be avoided completely in VoIP that uses Internet for all or part of the voice-data traffic.
Q. What if the customer experiences any technical issues with Integrated VoIP?
Q. What if the customer experiences any technical issues with Integrated VoIP?
A. Follow the standard Technical Support escalation process.
Last updated January 18, 2013